Spray drying is a process that disperses raw liquid into fine droplets via an atomizer. Powdered products are obtained through direct contact between droplets and hot air or other gases. The raw materials can be solutions, emulsions, suspensions, melts or pastes. Finished products can be processed into powder, granules, hollow spheres or agglomerates as required.
The centrifugal spray dryer adopts hot air circulation and concurrent flow centrifugal atomization design. Air is filtered through primary and medium-efficiency filters, heated up and delivered to the air distributor at the dryer top. Hot air enters the drying chamber evenly in a spiral pattern.
Liquid materials are pumped to the high-speed centrifugal atomizer mounted on the tower top. Under centrifugal force, materials are atomized into tiny droplets. The droplets flow concurrently with hot air and turn into finished products within an extremely short time.
Final products are continuously collected from the tower bottom and cyclone separator. Exhaust gas is dedusted and discharged by the induced draft fan.
Working Principle of Centrifugal Spray Dryer
The centrifugal spray dryer atomizes feed materials into fine droplets by centrifugal force generated from high-speed rotating atomizers. The droplets make instant contact with hot air distributed via the volute hot air distributor and get dried rapidly.
Feed liquid is thrown out from the edge of the high-speed rotating disc at a linear speed over 110m/s for atomization. The relatively large atomized droplet size requires a drying tower with a large inner diameter. Droplets feature uniform particle dimension after centrifugal ejection. They are dried immediately upon contact with hot air and mostly form hollow fine powder with consistent and relatively small particle size.
Widely applied in chemical, food, pharmaceutical and other industrial sectors, the dryer handles raw materials with diverse properties to produce finished goods meeting customized specifications. Accordingly, differences exist in technological procedures, process layout, equipment structure, operating parameters and auxiliary accessories.
Multiple options are available for product separation and recovery devices, including standard and combined cyclone separators, bag filters, cyclone-bag filter assemblies, cyclone-wet dust collector combinations and bag-wet dust collector combinations. Matching recovery units can be customized based on material characteristics and client demands.
Optional post-processing systems such as ZLG vibrating fluidized bed secondary drying system, pneumatic conveying, dehumidification, batching and powder screening systems can be equipped to satisfy varied production requirements.
Features of Centrifugal Spray Dryer
Drawing on advanced technologies and leveraging years of experience and technological innovation, Longxin Drying continuously optimizes centrifugal spray dryers and has obtained multiple patents including ZL202122093525.2 and ZL202321448173.0. The equipment sells well domestically and is exported overseas.
Users confirm that finished products achieve ideal performance in moisture content, color, fragrance, particle size, solubility, specific gravity and other key indicators.
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Fast drying speed. Atomization greatly expands material surface area. Around 95% to 98% moisture evaporates instantly upon contact with hot air within several seconds, making it ideal for heat-sensitive materials.
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Drying takes place in hot air, so finished products maintain spherical shape similar to original droplets with excellent dispersibility, fluidity and solubility. The machine runs steadily with easy parameter adjustment and automatic operation access.
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Simplified production process and convenient operation. Liquid materials with moisture content from 40% to 60%, up to 90% for special materials, can be dried into powder and granules in one pass. No crushing or screening is required afterwards, cutting working procedures and improving product purity. It creates clean working conditions and effectively prevents dust dispersion.
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Product particle size, bulk density and moisture content can be adjusted within a certain range by modifying operating parameters for simple control and management.
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It processes diverse raw materials such as solutions, slurry, emulsions, suspensions, pastes, melts and filter cakes.
Application Scope of Centrifugal Spray Dryer
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Chemical Products
Polyaluminium chloride, disperse dye, reactive dye, organic catalyst, white carbon black, laundry detergent, zinc sulfate, silicon dioxide, sodium metasilicate, potassium fluoride, calcium carbonate, potassium sulfate, inorganic catalyst, various waste liquids
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Food Industry
Whole milk powder, casein, cocoa milk powder, milk substitute powder, egg white & yolk powder;
Oatmeal, chicken essence, instant tea, condiment, meat extract, protein, soybean protein, peanut protein, protein hydrolysate;
Corn steep liquor, corn starch, glucose, pectin, maltose, potassium sorbate, pumpkin powder
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Pharmaceuticals
Chinese herbal extract, medicinal glue, yeast, vitamin, antibiotic, amylase, lipase
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Plastic Resins
AB latex, ABS latex, urea-formaldehyde resin, phenolic resin, melamine formaldehyde resin, polyethylene, polyvinyl chloride
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Detergents
High-grade laundry powder, ordinary washing powder, soap powder, soda powder, emulsifier, whitening agent, phosphate agent
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Ceramics
Alumina, zirconia, magnesium oxide, titanium oxide, magnesium titanate, kaolin, various ferrites and metal oxides
Technical Parameters of Centrifugal Spray Dryer
| Model / Parameter |
LPG-5 |
LPG-25 |
LPG-50 |
LPG-100 |
LPG-150 |
LPG-200 |
LPG-500 |
LPG-800 |
LPG-1000 |
LPG-2000 |
LPG-3000 |
LPG-4500 |
LPG-6500 |
| Inlet Temperature (°C) |
140-350 (automatic control) |
| Outlet Temperature (°C) |
80-90 |
| Atomization Type |
High-speed centrifugal atomizer (mechanical drive or infinitely variable frequency speed control optional) |
| Water Evaporation (kg/h) |
5 |
25 |
50 |
100 |
150 |
200 |
500 |
800 |
1000 |
2000 |
3000 |
4500 |
6500 |
| Atomizer Speed (rpm) |
25000 |
18000 |
18000 |
18000 |
18000 |
15000-18000 |
13000-18000 |
| Atomizer Disc Diameter (mm) |
60 |
120 |
150 |
180-210 |
Determined according to process requirements |
| Max. Electric Heating Power (kW) |
8 |
31.5 |
120 |
81 |
99 |
- |
| Powder Recovery Rate (%) |
≥95 |
| Occupied Length (m) |
1.6 |
4 |
4.5 |
5.2 |
7 |
7.5 |
12.5 |
13.5 |
14.5 |
- |
| Occupied Width (m) |
1.1 |
2.7 |
2.8 |
3.5 |
5.5 |
6 |
8 |
12 |
14 |
Determined according to process flow, plant conditions and user requirements |
| Tower Body Height (m) |
1.75 |
4.5 |
5.5 |
6.7 |
7.2 |
8 |
10 |
11 |
15 |
| Nozzle Hoisting Height (m) |
-- |
2.5 |
2.5 |
3.2 |
3.2 |
3.2 |
3.2 |
3.2 |
3.2 |
Note: The water evaporation capacity is related to material properties, hot air inlet temperature and outlet temperature. When the outlet temperature is 90℃, the water evaporation curve is shown in the figure above (for model selection reference only). Parameters are subject to change without prior notice due to continuous product updates.
Order Instructions for Centrifugal Spray Dryer
- Name and physical properties of liquid material: solid content (or moisture content), viscosity, surface tension, pH value, etc.
- Product characteristics: bulk density of dried powder, allowable residual moisture content, particle size range, maximum tolerable temperature.
- Special requirements (if any): specific gravity range, color, fragrance and others.
- Production capacity and daily working hours.
- Available energy sources: steam pressure, electricity, coal, fuel oil, natural gas, liquefied gas and other combustibles.
- Control requirements: control modes of inlet & outlet air temperature, feeding system and air hammer, as well as overall system control scheme.
- Material collection requirements: select cyclone separator, bag filter, wet dust collector and other devices according to product features and site conditions.
- Other special demands: workshop space, height limit, special power supply specifications, etc.
Note: Clients may provide partial information based on actual conditions. Remaining parameters can be confirmed through tests or negotiation based on professional experience.
Process Flow Chart 1 - Standard Type
Process Flow Chart 2 - Cooling Conveying & Centralized Collecting
Process Flow Chart 3 - Cold Wall & Air Sweeping & Cooling Conveying & Centralized Collecting
